This invention generally relates to internal combustion engines with a supercharger, and more particularly, the present invention relates to a method of controlling engine operation by preventing the pressure of supercharged intake air from being increased beyond a given value.
In an internal combustion engine equipped with a supercharger of the type driven by the exhaust gasses, the greater amount of the exhaust gasses the higher supercharging pressure is produced. However, supercharging pressure should be limited within a given value because excessively high pressure may damage the engine. According to one conventional system for suppressing such an excessive increase in supercharging pressure, the amount of exhaust gasses passing through the turbine of the supercharger is controlled so that the rotational speed of the turbine is suppressed within a predetermined limit. This conventional system or method has suffered from various problems. Namely, the system is too complex, and therefore, expensive. Furthermore, since the conventional system has to control the amount of exhaust gasses under high temperature conditions, the system has a problem in connection with durability.